Field of the Invention
The present invention relates to a wireless communication system, more particularly, a method for transmitting sidelink terminal information of terminal in a wireless communication system and the terminal utilizing the method.
Related Art
In International Telecommunication Union Radio communication sector (ITU-R), a standardization task for International Mobile Telecommunication (IMT)-Advanced, that is, the next-generation mobile communication system since the third generation, is in progress. IMT-Advanced sets its goal to support Internet Protocol (IP)-based multimedia services at a data transfer rate of 1 Gbps in the stop and slow-speed moving state and of 100 Mbps in the fast-speed moving state.
For example, 3rd Generation Partnership Project (3GPP) is a system standard to satisfy the requirements of IMT-Advanced and is preparing for LTE-Advanced improved from Long Term Evolution (LTE) based on Orthogonal Frequency Division Multiple Access (OFDMA)/Single Carrier-Frequency Division Multiple Access (SC-FDMA) transmission schemes. LTE-Advanced is one of strong candidates for IMT-Advanced.
There is a growing interest in a Device-to-Device (D2D) technology in which devices perform direct communication. In particular, D2D has been in the spotlight as a communication technology for a public safety network. A commercial communication network is rapidly changing to LTE, but the current public safety network is basically based on the 2G technology in terms of a collision problem with existing communication standards and a cost. Such a technology gap and a need for improved services are leading to efforts to improve the public safety network.
The public safety network has higher service requirements (reliability and security) than the commercial communication network. In particular, if coverage of cellular communication is not affected or available, the public safety network also requires direct communication between devices, that is, D2D operation.
D2D operation may have various advantages in that it is communication between devices in proximity. For example, D2D UE has a high transfer rate and a low delay and may perform data communication. Furthermore, in D2D operation, traffic concentrated on a base station can be distributed. If D2D UE plays the role of a relay, it may also play the role of extending coverage of a base station.
In LTE-A, terminal-to-terminal interface is referred to as a sidelink. Actions that a terminal can perform on a sidelink include sidelink communication and sidelink discovery.
In a prior art, it is assumed that the terminal always transmits a sidelink discovery signal only in the serving cell, and a configuration of the sidelink discovery signal is also received only in the serving cell. However, in the future wireless communication system, the terminal may transmit the sidelink discovery signal in the non-serving cell of the non-serving frequency on which the terminal is not subject to the service. That is, the terminal may perform the sidelink action at a frequency other than the serving frequency.
The terminal informs the network of the sidelink information through the sidelink terminal information. In conventional sidelink terminal information, the terminal cannot inform the frequency or cell that the terminal is interested in transmitting the sidelink discovery signal. Thus, it is inefficient to directly apply the conventional sidelink terminal information to future wireless communication systems.
In addition, the network cannot know the frequency or cell in which the terminal is interested in performing the sidelink action, and thus the sidelink action related configuration provided by the cell on the corresponding frequency cannot be known. Accordingly, there is a problem that it is difficult for the network to assist the sidelink action of the terminal.